Liquid fuel spraying nozzles



PM W Dec. 20, 1960 D. GASCOIGNE LIQUID FUEL SPRAYING NOZZLE S Filed July 8, 1959 LIQUID FUEL SPRAYING N OZZLES Denis Gascoigne, Fulwood, Preston, England, assignor to Joseph Lucas (Industries) Limited, Birmingham, England Filed July 8, 1959, Ser. No. 825,788

Claims priority, application Great Britain July 9, 1958 1 Claim. (Cl. 239-403) This invention relates to liquid fuel spraying nozzles of the pintle type comprising an elastic flexible diaphragm having a central discharge orifice therein, and a stationary closure member against which the diaphragm abuts when no flow occurs.

The object of the invention is to enable improved nebulisation of the emergent fuel jet to be obtained in a simple manner.

A nozzle of the kind aforesaid and in accordance with the invention comprises the combination with the discharge end of the body part of the nozzle, of a cap having therein a central discharge orifice and adapted to form with the diaphragm a chamber in which a swirling stream of air can be produced.

In the accompanying drawings:

Figure 1 is a longitudinal section of a nozzle embodying the invention.

Figure 2 is a fragmentary view illustrating to a larger scale than Figure l a portion of the diaphragm and the associated closure member.

In the example illustrated by the drawings, an outer hollow body part a of substantially cylindrical form is adapted at one end for attachement to a fuel supply pipe. At the other end this part is enlarged to form a cylindrical cavity 12 for accommodating end portions of other component parts of the nozzle. A portion of the outer body part between its ends is internally screwthreaded and to this portion is secured an inner body part c having an enlarged end which is contained in the said cavity b of the outer part a. The body part c has secured to it, or is formed integrally with a hollow part c in which are formed slots which are covered by a filter c2 through which fuel can enter this part. Into the opposite end of the part 01 is screw-threaded a third hollow part d on the outer end of which is secured the elastic flexible diaphragm e and within the said third part d is contained a fourth hollow part 1 which forms the pintle. On the latter is formed a closure member g which latter by contact with the rear side of the diaphragm closes the central hole h in the diaphragm when the nozzle is not in action. Further there is formed on the closure member a thin axial stern i which extends through the hole in the diaphragm and terminates in a conical head k adapted to cause the emergent jet to spread in the form of a hollow cone.

In the enlarged end of the second mentioned body part c is screwed a hollow cap m adapted to close the enlarged end of the first mentioned body part a which end serves as an annular air chamber. Also the cap is shaped to form with the part d carrying the diaphragm an air chamber n which communicates with the other air chamber through a plurality of tangentially arranged ports 0.

'1 5 The arrangement is such that the liquid fuel entering he first and second mentioned body parts passes into the nterior of the part f and thence through ports p therein ice to an annular space q formed by the part d carrying the diaphragm. By pressure of the fuel on the diaphragm, the latter is moved out of contact with the closure member g and the jet then issues through the hole h in the diaphragm.

The air supplied to the combustion chamber from a blower flows over the exterior of the body part a of the nozzle, and a part of this air enters the above mentioned annular air chamber b of the nozzle through holes r formed in the outer portion of the body part. From this chamber the air passes through the tangential ports 0 to the air chamber it around the jet and by its swirling motion serves to promote rapid nebulisation of the fuel, the mixture of air and fuel being then discharged to the combustion chamber through the central hole s in the cap m.

The invention is not, however, restricted to the specific example above described, as subordinate and unessential details of construction of the various components may be varied to suit different requirements.

Having thus described my invention what I claim as new and desire to secure by Letters Patent is:

A liquid fuel spraying nozzle comprising in combination a substantially cylindrical hollow body part provided at one end with a fuel inlet, a hollow member secured coaxially within said body part and having its end portion remote from said fuel inlet surrounded by, and separated by an annular space from, the corresponding end portion of said hollow body part, the latter being provided with ports through which air under pressure is admissible to said annular space, a hollow cap closing the outer end of said annular space and provided with a central discharge opening, and also with tangential ports leading from said annular space to the interior of said hollow cap, a pintle support of hollow form secured coaxially within said hollow member with one end within said hollow cap, a hollow pintle secured within the hollow support and having one end in communication with the first mentioned end of said hollow body part, the other end of said hollow pintle being surrounded by and spaced from the end of said hollow support within said hollow cap, and being provided with outlet ports, an elastic flexible diaphragm secured to the last mentioned end of said hollow support and forming with said cap a chamber to which streams of swirling air are admissible from said annular space through the tangential ports in said cap, the diaphragm being provided with a central hole, and a closure member provided on the ported end of said pintle to serve by contact with the portion of said diaphragm around the central hole therein to close said central hole when the nozzle is out of action, said diaphragm being separable from said closure member by fuel pressure in the adjacent end of said hollow support when the nozzle is in action, and said closure member having thereon an axial stem which extends with clearance through the central hole in the diaphragm, and which terminates in a conical head whereby fuel emerging from said central hole is caused to spread in the form of a hollow cone.

References Cited in the file of this patent UNITED STATES PATENTS 2,144,874 Edwards Jan. 24, 1939 2,701,164 Purchas et al. Feb. 1, 1955 2,893,647 Wortman July 7, 1959 FOREIGN PATENTS 504,830 Italy Dec. 14, 1954 909,736 France Jan. 7, 1946 

